// This holds an image as 8bpp RGBA.
struct image_info
{
- image_info() : rows(NULL), hasTransparency(true), is9Patch(false), allocRows(NULL) { }
+ image_info() : rows(NULL), is9Patch(false), allocRows(NULL) { }
~image_info() {
if (rows && rows != allocRows) {
free(rows);
}
free(allocRows);
}
+ free(info9Patch.xDivs);
+ free(info9Patch.yDivs);
+ free(info9Patch.colors);
}
png_uint_32 width;
png_uint_32 height;
png_bytepp rows;
- bool hasTransparency;
-
// 9-patch info.
bool is9Patch;
Res_png_9patch info9Patch;
return c;
}
-static void examine_image(image_info* image)
-{
- bool hasTrans = false;
- for (int i=0; i<(int)image->height && !hasTrans; i++) {
- png_bytep p = image->rows[i];
- for (int j=0; j<(int)image->width; j++) {
- if (p[(j*4)+3] != 0xFF) {
- hasTrans = true;
- break;
- }
- }
- }
-
- image->hasTransparency = hasTrans;
-}
-
static status_t do_9patch(const char* imageName, image_info* image)
{
image->is9Patch = true;
int H = image->height;
int i, j;
- int maxSizeXDivs = (W / 2 + 1) * sizeof(int32_t);
- int maxSizeYDivs = (H / 2 + 1) * sizeof(int32_t);
+ int maxSizeXDivs = W * sizeof(int32_t);
+ int maxSizeYDivs = H * sizeof(int32_t);
int32_t* xDivs = (int32_t*) malloc(maxSizeXDivs);
int32_t* yDivs = (int32_t*) malloc(maxSizeYDivs);
uint8_t numXDivs = 0;
return true;
}
+static void dump_image(int w, int h, png_bytepp rows, int color_type)
+{
+ int i, j, rr, gg, bb, aa;
+
+ int bpp;
+ if (color_type == PNG_COLOR_TYPE_PALETTE || color_type == PNG_COLOR_TYPE_GRAY) {
+ bpp = 1;
+ } else if (color_type == PNG_COLOR_TYPE_GRAY_ALPHA) {
+ bpp = 2;
+ } else if (color_type == PNG_COLOR_TYPE_RGB || color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
+ // We use a padding byte even when there is no alpha
+ bpp = 4;
+ } else {
+ printf("Unknown color type %d.\n", color_type);
+ }
+
+ for (j = 0; j < h; j++) {
+ png_bytep row = rows[j];
+ for (i = 0; i < w; i++) {
+ rr = row[0];
+ gg = row[1];
+ bb = row[2];
+ aa = row[3];
+ row += bpp;
+
+ if (i == 0) {
+ printf("Row %d:", j);
+ }
+ switch (bpp) {
+ case 1:
+ printf(" (%d)", rr);
+ break;
+ case 2:
+ printf(" (%d %d", rr, gg);
+ break;
+ case 3:
+ printf(" (%d %d %d)", rr, gg, bb);
+ break;
+ case 4:
+ printf(" (%d %d %d %d)", rr, gg, bb, aa);
+ break;
+ }
+ if (i == (w - 1)) {
+ NOISY(printf("\n"));
+ }
+ }
+ }
+}
+
+#define MAX(a,b) ((a)>(b)?(a):(b))
+#define ABS(a) ((a)<0?-(a):(a))
-static void analyze_image(image_info &imageInfo, png_colorp rgbPalette, png_bytep alphaPalette,
+static void analyze_image(const char *imageName, image_info &imageInfo, int grayscaleTolerance,
+ png_colorp rgbPalette, png_bytep alphaPalette,
int *paletteEntries, bool *hasTransparency, int *colorType,
png_bytepp outRows)
{
int w = imageInfo.width;
int h = imageInfo.height;
- bool trans = imageInfo.hasTransparency;
int i, j, rr, gg, bb, aa, idx;
uint32_t colors[256], col;
int num_colors = 0;
+ int maxGrayDeviation = 0;
bool isOpaque = true;
bool isPalette = true;
// 1. Every pixel has R == G == B (grayscale)
// 2. Every pixel has A == 255 (opaque)
// 3. There are no more than 256 distinct RGBA colors
+
+ // NOISY(printf("Initial image data:\n"));
+ // dump_image(w, h, imageInfo.rows, PNG_COLOR_TYPE_RGB_ALPHA);
+
for (j = 0; j < h; j++) {
png_bytep row = imageInfo.rows[j];
png_bytep out = outRows[j];
gg = *row++;
bb = *row++;
aa = *row++;
- if (!trans) {
- // Ignore the actually byte and assume alpha == 255
- aa = 0xff;
+
+ int odev = maxGrayDeviation;
+ maxGrayDeviation = MAX(ABS(rr - gg), maxGrayDeviation);
+ maxGrayDeviation = MAX(ABS(gg - bb), maxGrayDeviation);
+ maxGrayDeviation = MAX(ABS(bb - rr), maxGrayDeviation);
+ if (maxGrayDeviation > odev) {
+ NOISY(printf("New max dev. = %d at pixel (%d, %d) = (%d %d %d %d)\n",
+ maxGrayDeviation, i, j, rr, gg, bb, aa));
}
// Check if image is really grayscale
if (isGrayscale) {
- if (rr != gg || rr != bb) {
- isGrayscale = false;
- }
+ if (rr != gg || rr != bb) {
+ NOISY(printf("Found a non-gray pixel at %d, %d = (%d %d %d %d)\n",
+ i, j, rr, gg, bb, aa));
+ isGrayscale = false;
+ }
}
// Check if image is really opaque
if (isOpaque) {
- if (aa != 0xff) {
- isOpaque = false;
- }
+ if (aa != 0xff) {
+ NOISY(printf("Found a non-opaque pixel at %d, %d = (%d %d %d %d)\n",
+ i, j, rr, gg, bb, aa));
+ isOpaque = false;
+ }
}
// Check if image is really <= 256 colors
*out++ = idx;
if (!match) {
if (num_colors == 256) {
+ NOISY(printf("Found 257th color at %d, %d\n", i, j));
isPalette = false;
} else {
colors[num_colors++] = col;
int bpp = isOpaque ? 3 : 4;
int paletteSize = w * h + bpp * num_colors;
+ NOISY(printf("isGrayscale = %s\n", isGrayscale ? "true" : "false"));
+ NOISY(printf("isOpaque = %s\n", isOpaque ? "true" : "false"));
+ NOISY(printf("isPalette = %s\n", isPalette ? "true" : "false"));
+ NOISY(printf("Size w/ palette = %d, gray+alpha = %d, rgb(a) = %d\n",
+ paletteSize, 2 * w * h, bpp * w * h));
+ NOISY(printf("Max gray deviation = %d, tolerance = %d\n", maxGrayDeviation, grayscaleTolerance));
+
// Choose the best color type for the image.
// 1. Opaque gray - use COLOR_TYPE_GRAY at 1 byte/pixel
// 2. Gray + alpha - use COLOR_TYPE_PALETTE if the number of distinct combinations
} else if (isPalette && (paletteSize < bpp * w * h)) {
*colorType = PNG_COLOR_TYPE_PALETTE;
} else {
- *colorType = isOpaque ? PNG_COLOR_TYPE_RGB : PNG_COLOR_TYPE_RGB_ALPHA;
+ if (maxGrayDeviation <= grayscaleTolerance) {
+ printf("%s: forcing image to gray (max deviation = %d)\n", imageName, maxGrayDeviation);
+ *colorType = isOpaque ? PNG_COLOR_TYPE_GRAY : PNG_COLOR_TYPE_GRAY_ALPHA;
+ } else {
+ *colorType = isOpaque ? PNG_COLOR_TYPE_RGB : PNG_COLOR_TYPE_RGB_ALPHA;
+ }
}
// Perform postprocessing of the image or palette data based on the final
bb = *row++;
aa = *row++;
- *out++ = rr;
+ if (isGrayscale) {
+ *out++ = rr;
+ } else {
+ *out++ = (png_byte) (rr * 0.2126f + gg * 0.7152f + bb * 0.0722f);
+ }
if (!isOpaque) {
*out++ = aa;
}
- }
+ }
}
}
}
static void write_png(const char* imageName,
png_structp write_ptr, png_infop write_info,
- image_info& imageInfo)
+ image_info& imageInfo, int grayscaleTolerance)
{
bool optimize = true;
png_uint_32 width, height;
int i;
png_unknown_chunk unknowns[1];
+ unknowns[0].data = NULL;
png_bytepp outRows = (png_bytepp) malloc((int) imageInfo.height * png_sizeof(png_bytep));
if (outRows == (png_bytepp) 0) {
png_set_compression_level(write_ptr, Z_BEST_COMPRESSION);
- NOISY(printf("Writing image %s: w = %d, h = %d, trans = %s\n", imageName,
- (int) imageInfo.width, (int) imageInfo.height,
- imageInfo.hasTransparency ? "true" : "false"));
+ NOISY(printf("Writing image %s: w = %d, h = %d\n", imageName,
+ (int) imageInfo.width, (int) imageInfo.height));
png_color rgbPalette[256];
png_byte alphaPalette[256];
bool hasTransparency;
int paletteEntries;
- if (optimize) {
- analyze_image(imageInfo, rgbPalette, alphaPalette, &paletteEntries, &hasTransparency,
- &color_type, outRows);
- switch (color_type) {
- case PNG_COLOR_TYPE_PALETTE:
- NOISY(printf("Image %s has %d colors%s, using PNG_COLOR_TYPE_PALETTE\n",
- imageName, paletteEntries,
- hasTransparency ? " (with alpha)" : ""));
- break;
- case PNG_COLOR_TYPE_GRAY:
- NOISY(printf("Image %s is opaque gray, using PNG_COLOR_TYPE_GRAY\n", imageName));
- break;
- case PNG_COLOR_TYPE_GRAY_ALPHA:
- NOISY(printf("Image %s is gray + alpha, using PNG_COLOR_TYPE_GRAY_ALPHA\n", imageName));
- break;
- case PNG_COLOR_TYPE_RGB:
- NOISY(printf("Image %s is opaque RGB, using PNG_COLOR_TYPE_RGB\n", imageName));
- break;
- case PNG_COLOR_TYPE_RGB_ALPHA:
- NOISY(printf("Image %s is RGB + alpha, using PNG_COLOR_TYPE_RGB_ALPHA\n", imageName));
- break;
- }
- } else {
- // Force RGB or RGB_ALPHA color type, copy transparency from input
- paletteEntries = 0;
- hasTransparency = imageInfo.hasTransparency;
- color_type = hasTransparency ? PNG_COLOR_TYPE_RGB_ALPHA : PNG_COLOR_TYPE_RGB;
+ analyze_image(imageName, imageInfo, grayscaleTolerance, rgbPalette, alphaPalette,
+ &paletteEntries, &hasTransparency, &color_type, outRows);
+
+ // If the image is a 9-patch, we need to preserve it as a ARGB file to make
+ // sure the pixels will not be pre-dithered/clamped until we decide they are
+ if (imageInfo.is9Patch && (color_type == PNG_COLOR_TYPE_RGB ||
+ color_type == PNG_COLOR_TYPE_GRAY || color_type == PNG_COLOR_TYPE_PALETTE)) {
+ color_type = PNG_COLOR_TYPE_RGB_ALPHA;
+ }
+
+ switch (color_type) {
+ case PNG_COLOR_TYPE_PALETTE:
+ NOISY(printf("Image %s has %d colors%s, using PNG_COLOR_TYPE_PALETTE\n",
+ imageName, paletteEntries,
+ hasTransparency ? " (with alpha)" : ""));
+ break;
+ case PNG_COLOR_TYPE_GRAY:
+ NOISY(printf("Image %s is opaque gray, using PNG_COLOR_TYPE_GRAY\n", imageName));
+ break;
+ case PNG_COLOR_TYPE_GRAY_ALPHA:
+ NOISY(printf("Image %s is gray + alpha, using PNG_COLOR_TYPE_GRAY_ALPHA\n", imageName));
+ break;
+ case PNG_COLOR_TYPE_RGB:
+ NOISY(printf("Image %s is opaque RGB, using PNG_COLOR_TYPE_RGB\n", imageName));
+ break;
+ case PNG_COLOR_TYPE_RGB_ALPHA:
+ NOISY(printf("Image %s is RGB + alpha, using PNG_COLOR_TYPE_RGB_ALPHA\n", imageName));
+ break;
}
png_set_IHDR(write_ptr, write_info, imageInfo.width, imageInfo.height,
}
png_write_info(write_ptr, write_info);
-
- if (!imageInfo.hasTransparency) {
- png_set_filler(write_ptr, 0, PNG_FILLER_AFTER);
- }
+ png_bytepp rows;
if (color_type == PNG_COLOR_TYPE_RGB || color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
- png_write_image(write_ptr, imageInfo.rows);
+ png_set_filler(write_ptr, 0, PNG_FILLER_AFTER);
+ rows = imageInfo.rows;
} else {
- png_write_image(write_ptr, outRows);
+ rows = outRows;
}
+ png_write_image(write_ptr, rows);
+
+// NOISY(printf("Final image data:\n"));
+// dump_image(imageInfo.width, imageInfo.height, rows, color_type);
png_write_end(write_ptr, write_info);
free(outRows[i]);
}
free(outRows);
+ free(unknowns[0].data);
png_get_IHDR(write_ptr, write_info, &width, &height,
&bit_depth, &color_type, &interlace_type,
read_png(printableName.string(), read_ptr, read_info, &imageInfo);
- examine_image(&imageInfo);
-
if (nameLen > 6) {
const char* name = file->getPath().string();
if (name[nameLen-5] == '9' && name[nameLen-6] == '.') {
goto bail;
}
- write_png(printableName.string(), write_ptr, write_info, imageInfo);
+ write_png(printableName.string(), write_ptr, write_info, imageInfo,
+ bundle->getGrayscaleTolerance());
error = NO_ERROR;